<I would agree that you don't have to care much about the quality of the
Corncrake recordings. The self-noise performance of the microphone is not a=
s
important as in other subjects. Very often it is possible to get very close
to the calling birds (certainly at night). Though, a more directional and
low-noise microphone would be useful for more distant recording situations.
The following sample has been recorded at a distance of a few meters :
http://www.avisoft-saslab.com/sounds/corncrak2.wav
At larger distances, the background noise level may slightly rise:
http://www.avisoft-saslab.com/sounds/corncrak.wav>
Yes Raimund but your examples here are made on a very expensive set up are
they not?
Surely you have to have some care about the quality of the recordings to ge=
t
the quality of the visual displays?
Martyn
Martyn Stewart
Bird and Animal Sounds Digitally Recorded at:
http://www.naturesound.org
N47.65543 W121.98428
Redmond. Washington. USA
Make every Garden a wildlife Habitat!
When the animals come to us,
Asking for our help,
Will we know what they are saying?
When the plants speak to us
In their delicate, beautiful language,
Will we be able to answer them?
When the planet herself
Sings to us in our dreams,
Will we be able to wake ourselves, and act?
-Gary Lawless
-----Original Message-----
From:
Sent: Wednesday, April 28, 2004 12:17 AM
To:
Subject: Re: [Nature Recordists] Corncrake
Hi Fran=E7ois,
I would agree that you don't have to care much about the quality of the
Corncrake recordings. The self-noise performance of the microphone is not a=
s
important as in other subjects. Very often it is possible to get very close
to the calling birds (certainly at night). Though, a more directional and
low-noise microphone would be useful for more distant recording situations.
The following sample has been recorded at a distance of a few meters :
http://www.avisoft-saslab.com/sounds/corncrak2.wav
At larger distances, the background noise level may slightly rise:
http://www.avisoft-saslab.com/sounds/corncrak.wav
It can be seen that the two birds use different temporal patterns. Both use
two alternating calls with different pulse counts. corncrak2.wav has the
pattern 18 =96 22 =96 18 =96 22 - ... , while corncrak.wav uses a 19 - 20 p=
attern.
I guess that most of information required for individual identification is
encoded in the temporal patterns of the calls (inter-call and inter-pulse
intervals, number of pulses in the alternating calls). So you could perhaps
use any simple sound analysis program that provides a waveform display (e.g=
.
Cool Edit / Audition, Goldwave or the free Avisoft-SASLab Light). These
applications require manual processing (you had to place the cursors
manually for measuring the temporal structure). If you need to process many
recordings, the manual processing might become very time-consuming. The
sound analysis software Avisoft-SASLab Pro would provide various tools for
measuring these parameters in an automated way. For instance, the newly
implemented Pulse Train Analysis tool could be used:
http://www.avisoft-saslab.com/pta.gif
However, one should note that such automated tools usually require good
recordings with reasonable signal-to-noise ratio's.
Regards,
Raimund Specht
Avisoft Bioacoustics
http://www.avisoft-saslab.com
> Hi,
>
> I'm working in Conservatoire des Sites Naturels de Picadie (France). This
> year, we launch a program 3 years about conservation of Corncrake (Crex
> crex). The main part of the programm is sensibilisation farmers during
> mowing. Also, we'll try to census Corncrake. I've heard that it is
> possible
> to make individual identification of corncrake by analysys calls. Do you
> know the minimum require equipment to record and analyse calls. I don't
> care
> about the quality of the record, I just want to identify individual birds=
.
>
> Thank you for your help.
>
> Fran=E7ois BOCA
> Conservatoire des Sites Naturels de Picardie
> FRANCE
>
>
>
>
> "Microphones are not ears,
> Loudspeakers are not birds,
> A listening room is not nature."
> Klas Strandberg
> Yahoo! Groups Links
>
>
>
>=20
>
--
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"Microphones are not ears,
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Yahoo! Groups Links
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